Daniele Tognetto

Capsulorhexis size and posterior capsule opacification

Purpose: Posterior capsule opacification (PCO) after intraocular lens (IOL) implantation has a multifactored pathogenesis. Capsulorhexis and capsular bag implantation of a one‐piece, biconvex poly(methyl methacrylate) (PMMA) IOL are likely to reduce the PCO incidence. This study was performed to determine whether an ideal capsulorhexis size able to reduce PCO incidence exists. Methods: A retrospective study of 107 patients who had extracapsular cataract extraction with capsulorhexis and capsular bag IOL implantation was carried out. The PCO site (central, paracentral, and peripheral) and degree (mild, moderate, and severe) were evaluated in relation to the capsulorhexis edge location relative to the IOL optic. Slitlamp biomicroscopy and photography and examination with a threemirror Goldmann lens were performed. Patients were divided into three groups. Group 1: capsulorhexis free edge located on the IOL optic for 360 degrees; Group 2: capsulorhexis free edge located asymmetrically on and peripherally to the IOL optic; Group 3: capsulorhexis free edge located peripherally to IOL optic for 360 degrees. Each group was divided into two subgroups; one received polyHema IOLs and the second, PMMA IOLs. Results: In Groups 1 and 2, the capsular transparency was higher than in Group 3 (P < .04). Central opacification percentage was lower in Group 1 than in Groups 2 and 3 (P < .04). No statistically significant differences between the polyHema and the PMMA subgroups were seen. Conclusions: Capsulorhexis with a slightly smaller diameter than the IOL optic appears to be better than a large‐size capsulorhexis in reducing the incidence of PCO.

Glistenings in foldable intraocular lenses

Purpose: To evaluate the formation of glistenings in foldable intraocular lenses (IOLs) of various materials after cataract surgery. Setting: University Eye Clinic of Trieste, Trieste, Italy. Methods: In this prospective study, 273 patients were randomized to have implantation of 1 of 7 types of foldable IOLs in the capsular bag after phacoemulsification. The IOLs were the CeeOn® Edge 911A (Pharmacia & Upjohn Co.), ACR6D® (Corneal), AcrySof® (Alcon), SI‐40NB (AMO), Hydroview® H60M (Storz), Sensar® (AMO), and Stabibag® (Ioltech). The presence of glistenings in the IOL optic was assessed by slitlamp evaluation 7, 30, 90, 180, 360, and 720 days after surgery. The glistenings were graded at each control. Results: Glistenings were observed in all IOL groups. The percentage of patients with glistenings ranged from 40.0% to 67.5%, with the percentage increasing up to 90 days after surgery and then becoming stable in most groups. The AcrySof group had a continuous increase over time. The mean grade of glistenings increased up to 180 days after surgery and then became stable in most groups. The AcrySof and 911A groups had a continuous increase over time. Conclusions: Glistening formation was observed in 7 different foldable IOLs. The AcrySof group had a higher percentage and a greater density of glistenings.

Postoperative Cellular Reaction on Various Intraocular Lens Materials

PURPOSE The presence of cellular deposits on the surface of intraocular lenses (IOLs) is a manifestation of: (1) the breakdown of the blood-aqueous barrier produced by surgery; and (2) foreign body reaction induced by lens implantation. The purpose of this study was to assess the presence of cellular deposits on the surfaces of various IOL materials. METHODS Fifty patients scheduled for cataract surgery were randomized into five groups of ten patients each and received IOLs of the following materials: conventional polymethylmethacrylate (PMMA), surface-passivated PMMA, heparin-surface modified PMMA, poly-hydroxyethylmethacrylate (HEMA) hydrogel and silicone. Patients were examined at 7 days, 30 days, 90 days, and 180 days after surgery. All eyes were observed first via slit-lamp and then using a contact specular microscope for photographic documentation. RESULTS Small, spindle-shaped cells were observed on all IOLs in the early postoperative period. Epithelioid cells appeared approximately 30 days after surgery on all PMMA IOLs, but most particularly on conventional PMMA IOLs. No cells were observed on poly-HEMA and silicone IOLs. CONCLUSIONS The decreased number of epithelioid cells discovered in the early postoperative period may indicate a reduction in the inflammatory process induced by surgery. The permanence of epithelioid cells on IOL surfaces may be a sign of foreign body reaction. The results of this study indicated that poly-HEMA and silicone IOLs showed fewer cellular deposits than PMMA IOLs, suggesting that they may be better tolerated than PMMA IOLs.

CORNEAL ENDOTHELIAL FUNCTION AFTER EXTRACAPSULAR CATARACT EXTRACTION AND PHACOEMULSIFICATION

Purpose: To compare the morphology and function of the corneal endothelium in the early postoperative period after extracapsular cataract extraction (ECCE) and phacoemulsification. Setting: University Eye Clinic of Trieste, Italy. Methods: In this prospective, randomized study of patients scheduled for cataract surgery, 40 patients were divided into two groups of 20 patients each. Group 1 had ECCE and Group 2, phacoemulsification; both had capsular bag intraocular lens (IOL) implantation. Preoperatively and 7 and 30 days postoperatively, a complete ophthalmological examination, endothelial specular microscopy, ultrasonic pachymetry, and anterior segment fluorophotometry were done. Visual acuity, endothelial cell density, cell size variation coefficient, corneal thickness, endothelial permeability coefficient, and endothelial pump function were studied. Results: Visual acuity was better 7 days after phacoemulsification than after ECCE, but no differences were observed after 30 days. No significant differences in postoperative loss of endothelial cells were found between the two groups. Coefficient of variation in size, corneal thickness, and endothelial permeability significantly increased in both groups 7 days postoperatively, but only in the ECCE group 30 days postoperatively; the differences between the two groups were statistically significant. Endothelial pump function significantly increased after 7 days in only the phacoemulsification group. Conclusions: Functional endothelial failure occurred in the early period after ECCE. Phacoemulsification seemed to minimize postoperative functional damage to the endothelium.

Corneal endothelial protection by different viscoelastics during phacoemulsification

Purpose: To evaluate corneal endothelium morphology and function after phacoemulsification using different viscoelastics. Setting: Eye Clinic, University of Trieste, Italy. Methods: This prospective, randomized study included results of preoperative and postoperative (7, 30, and 90 days) examinations of 66 patients scheduled for phacoemulsification without other ocular pathology; 8 patients were excluded. Patients were randomly assigned to one of four groups based on type of viscoelastic used: 1% sodium hyaluronate (Healon®); 1.4% sodium hyaluronate (Healon GV®); 4% sodium chondroitin sulfate‐3% sodium hyaluronate (Viscoat®); 2% hydroxypropyl methylcellulose (Hymecel®). Mean cell density and cell size variation coefficient were determined by specular microscopy; central corneal thickness, by ultrasonic pachymetry; and endothelial permeability coefficient and active pump function, by anterior segment fluorophotometry. Results: There were no significant differences in postoperative mean cell loss among the groups. The cell size variation coefficient was altered in all groups 7 days after surgery and was still impaired at 30 days in the Hymecel group. A significant increase in mean corneal thickness, endothelial permeability, and active pump function occurred in the Healon and Hymecel groups 7 days after surgery. These parameters were still altered 30 days after surgery in the Hymecel group. Endothelial functional alterations did not occur in the Healon GV or Viscoat group. Conclusion: Viscoat and Healon GV are effective in minimizing functional damage of endothelial structure in the early and medium‐term postoperative period.

Staining of the internal limiting membrane with intravitreal triamcinolone acetonide.

Purpose: To evaluate the use of triamcinolone acetonide to stain the internal limiting membrane (ILM) during vitreoretinal surgery. Methods: A prospective clinical interventional case series study was performed, including 16 patients who underwent pars plana vitrectomy. Seven patients had proliferative diabetic retinopathy with macular edema. Seven patients had epiretinal membranes. One patient had a retinal detachment with a cystoid macular edema and proliferative vitreoretinopathy. One patient had a pseudophakic cystoid macular edema. After vitrectomy, 2 mL triamcinolone acetonide suspension was injected into the vitreous cavity. The ILM was peeled, as it was evidenced by the particles of triamcinolone that adhered to its surface. The ultrastructure of tissue harvested during surgery was analyzed using transmission electron microscopy in selected cases to confirm the presence or absence of ILM. Results: After the injection of triamcinolone, the visualization of the vitreous base and hyaloid was excellent in all patients. The particles of triamcinolone deposited on the retinal surface enabled the ILM to be stained. Once removed, the ILM was clearly distinguishable, floating in the vitreous cavity with particles of triamcinolone adhering to its surface. Ultrastructural analysis of tissue collected during vitrectomy confirmed that the removed tissue represented ILM. Conclusion: We observed that triamcinolone acetonide can be useful in staining the internal limiting membrane, thus greatly facilitating the retinal ILM peeling. The absence of particles of triamcinolone on the underlying retina enables the area where the ILM has already been removed to be identified.

Retinal detachment after cataract extraction and refractive lens exchange in highly myopic patients

Purpose: To assess the refractive effects and incidence of postoperative complications in patients with high myopia after cataract extraction. Setting: University Eye Clinic, Trieste, Italy. Methods: This noncomparative retrospective study comprised all eyes (N = 388) having cataract extraction and implantation of an intraocular lens with a power less than 11.0 diopters (D) between 1986 and 1999. The preoperative and postoperative refractions; preoperative, postoperative, and final best corrected visual acuity (BCVA); and postoperative complications were analyzed. The mean follow‐up was 47.16 months ± 32.83 (SD) (range 8 to 146 months). Results: Phacoemulsification was performed in 237 eyes, extracapsular cataract extraction in 147 eyes, and intracapsular cataract extraction in 4 eyes. The mean preoperative BCVA was 0.20 ± 0.21 and the mean postoperative BCVA, 0.58 ± 0.32. At the final evaluation, the mean BCVA was 0.50 ± 0.33. The mean refraction was −15.95 ± 5.86 D preoperatively and −2.00 ± 1.62 D postoperatively. One eye (0.26%) developed a retinal detachment postoperatively. Of the 127 eyes (32.73%) having a neodymium:YAG laser capsulotomy for posterior capsule opacification, 1 had a macular retinal hole. Posterior detachment of the vitreous occurred in 78.6% of cases. Peripheral retinal photocoagulation was required in 8 cases postoperatively. Conclusions: Refractive lens exchange led to good functional results and a low incidence of postoperative complications and can thus be regarded as a viable technique to correct high myopia associated with cataract. However, further study is required before it can be routinely recommended for the correction of high myopia in eyes with a transparent crystalline lens.

Biocompatibility of hydrophilic intraocular lenses.

Purpose: To assess the biocompatibility of 3 hydrophilic acrylic intraocular lenses (IOLs) by evaluating the postoperative cell reaction on the IOL surface, anterior capsule opacification (ACO) rate, and presence of membrane growth over the anterior IOL surface. Setting: University Eye Clinic of Trieste, Trieste, Italy. Methods: In this prospective study, 73 patients were randomized to receive 1 of 3 types of hydrogel IOLs after phacoemulsification: Storz Hydroview H60M, Corneal ACR6D, or Ioltech Stabibag. To analyze and photograph the anterior IOL surface, slitlamp biomicroscopy and specular microscopy were performed 7, 30, 90, and 180 days after surgery. Small, epithelioid, and giant inflammatory cell reaction was evaluated. In addition, ACO and membrane growth on the anterior IOL surface were assessed. Results: Low inflammatory cell adhesion was observed on the anterior surface of all 3 IOLs. The Stabibag group had a significantly higher grade of small inflammatory cell reaction 7 and 30 days after surgery. A significantly higher rate of ACO was observed in the ACR6D group. The Hydroview and ACR6D groups had a significantly higher percentage of membrane growth from the capsulorhexis edge onto the anterior IOL surface than the Stabibag group. Conclusions: Clinically, the 3 hydrophilic IOLs behaved in a different manner, showing the different forms of biocompatibility. Results indicate that a different chemical composition determines correspondingly different protein absorption on IOL surfaces. This might result in a different adhesion pattern and spreading of lens epithelial and inflammatory cells.

Efficacy of diclofenac eyedrops in preventing postoperative inflammation and long-term cystoid macular edema

Purpose: To compare the efficacy and tolerance of diclofenac 0.1 % eyedrops with a regimen that included a brief course of steroids in the treatment of postoperative inflammation after extracapsular cataract surgery and posterior chamber intraocular lens implantation. A second objective was to compare the efficacy of diclofenac 0.1% eyedrops in the same patients and control group in preventing cystoid macular edema (CME). Setting: Eight university/hospital centers and one company in Italy. Methods: The multicenter, controlled, randomized, prospective, double‐blind study included 281 patients. All were evaluated at baseline, at surgery, and after 1, 5, 36, 67, and 140 days. Postoperative inflammation was measured by the clinical assessment of inflammation: conjunctival hyperemia, ciliary flush, Tyndall effect, and cells in the anterior chamber. Fluorescein angiography was performed to evaluate the presence/absence of CME before surgery and after 36 and 140 days. Results: During follow‐up, no differences in intraoperative pressure were observed within or between groups or between operated and fellow eyes. No statistically significant between‐group differences in postoperative inflammation were found. After 36 days, angiographic CME was found in 9 patients (6.43%) in the diclofenac group and 20 (15.15%) in the control group (P = .033) with a relative risk for developing CME of 0.40 (Cl95 0.19 to 0.84). At the end of follow‐up, it was found in 4 patients in the diclofenac group (3.31%) and 10 (9.26%) in the control group (P = .05) with a relative risk of 0.36 (Cl95 0.12 to 0.90). Conclusion: Diclofenac sodium was as effective as the control regimen in controlling postoperative inflammation after cataract surgery. It also had a protective effect on the development of angiographic CME after 36 and 140 days.

Lens epithelial cell reaction after implantation of different intraocular lens materials: Two-year results of a randomized prospective trial

PURPOSE To determine the influence of intraocular lens (IOL) material on anterior capsular opacification and membrane growth over the anterior IOL surface in patients who have undergone standardized small-incision cataract surgery and foldable IOL implantation in the capsular bag. DESIGN Randomized controlled trial. PARTICIPANTS Eighty-eight cataract patients (88 eyes). METHODS Patients were randomly assigned to receive one of four different foldable IOLs after phacoemulsification: Storz Hydroview H60M, Corneal ACR6D, AMO SI40NB, and Alcon AcrySof MA60BM. Examinations on days 7, 30, 90, 180, 360, and 720 after surgery included ophthalmologic examination, slit-lamp biomicroscopy, and photography using red reflex and focal illumination of the anterior IOL surface. MAIN OUTCOME MEASURES Best-corrected visual acuity was measured at each examination. In addition, the anterior capsule opacification and the membrane growth on the anterior IOL surface were graded according to a subjective method by the same researcher. RESULTS The fibrosis of the anterior capsule was more frequently observed in the group using Corneal ACR6D and AMO SI40NB. The Hydroview and ACR6D groups showed a higher percentage of cases with membrane growth from the rhexis edge on the anterior IOL surface. AcrySof showed the lowest presence of fibrosis of the anterior capsule, and no membrane growth was noted. CONCLUSIONS Anterior capsule opacification is an index of IOL biocompatibility. The natural location of lens epithelial cells (LECs) precludes the possibility of the IOLs design influencing the anterior capsule behavior. The local response of LECs varies according to the IOL studied. This may be related to the chemical and physical properties of the materials used in the different IOLs.